You can put this solution on YOUR website! Let a = Ann's present age
Let b = Bill's age
:
Write an equation for each statement.
:
"Ann's age is seven tenths of Bill's age."
a = .7b
:
"In 4 years Ann's age will be eight-elevenths of Bills age."
a + 4 = (b + 4)
Multiply both sides by 11, get rid of the annoying denominator
11(a + 4) = 8(b + 4)
11a + 44 = 8b + 32
11a = 8b + 32 - 44
11a = 8b - 12
Replace a with .7b
11(.7b) = 8b - 12
7.7b = 8b - 12
7.7b - 8b = -12
-.3b = -12
b =
b = +40 yrs old is Bill
:
:
:
Check solution:
a = .7(40)
a = 28 yrs
"In 4 years Ann's age will be eight-elevenths of Bills age."
28 + 4 = (40 + 4)
32 = *44
32 = 8 * 4
